Fornia



dan, 16, 1923.l 1,442,552

E. E. WCKERSHAM. MA|N FRAME SUSPENSION PoR TRAcToRs.

ORIGINAL FILED AUG. l5, 1918. 2 sHEETsjsl-{EET l E. E( WICKERSHAM. MAIN FRAME, SUSPENSION FOR TRAcToRs,

Jan.l 16

ORIGnNAL F|LED AUG. 15, 1918. 2 sHr-:'Tvs-SHEE-T 2 E trim IN VEN TOR.

` A TTORNEYS Patented Jan. 16, 1923.

PATENT orifice.

ELMER E. WICKERSHAM, OF STOCKTON, CALIFORNIA, ASSIGNOB T0 THE HOLT MANU- FACTURING COMPANY, 0F STOCKTON, CALIFORNIA, A CORPORATION OF CALI- FORNIA.

MAIN-FRAME SUSPENSION FOR 'FB/ACTORS.

Application filed August 15, 19,18, Serial 116,249,962. Renewed June l,

To fic/tom if may concern lle it known that I, ELMER l'ronna' uemir, a` citizen of the United States, residing at Stockton, in the county' of San Joaquin and State of California, have invented new and useful' Improvements in Main-Frame Suspensions for Tractors, of which the following` is a specification.

This invention relates to' a tractor, and particularly pertains to means for resiliently suspending` the tractor frame from self-laying` track trucks] `In a copending application, Serial No. 249,611, tiled August 13th, 1918,` I have shown and described an equalizer mechanism comprising a rock shaft journaled on the main frameand having connections with the truck mechanismssuch that an upward movement of one truck imparts a downward movement to the other. The present application embodies the same idea, but discloses a simpler formA of device wherein the gears shown inthe above-mentionedappli-l cation have been omitted.

The invention is illustrated by way of example in the accompanying drawings, in which-` Fig. 1 is a View in side elevation, illus trating a tractor equipped with the frame suspension with which the present invention `is concerned.` y

Fig. A2 is a View in plan, illustrating the frame suspension mechanism.

Fig. 3 is a view in elevation, illustrating one end of the equalizer mechanism and disclosing its connection with themain frame and a track truck.

Fig. 4 is a fragmentary view in side'elevation, illustrating the complete equalizer mechanism.

Referring more particularly to the drawings, 10 indicates a main frame which is adapted to be supported upon its opposite sides by melf-laying truck units 11. Each of these units comprises a front idler wheel 12, a rear driving' sprocket wheel 13 and an endless chain track 141 passing around said wheels. The front idler wheel is provided with an axle `suitably housed within a bearing This bearing is mounted at the forward end of a roller truck frame 16. lThe roller truck frame carries a series of load-supporting rollers 17 which travel along the lower run of the chain track, The

1921. Serial N0. 474,293.

rear ends ofthe roller frames 16 are provided with standards 1S which vcarry a transverse rock shaft 19.' This shaft is also secured within hangers 20 depending from the main frame.

The previously described construction permits vertical swinging movement of the roller truck frames. It willl beunderstood, however, that other constructions may be used and that, if desired, the roller truck frames may be formed of articulated truck sections rather than a single rigid frame member. The forward ends of the roller truck frames `are connected with the main frame by means of the equalizer mechanism shown in Figs. 2, 3 and i This mechanism consists of a transverse shaft 21 which is rotatably supported with-H in bearings 22 bolted to the under face of" each of the longitudinal frame members of the main frame. Fixed to the shaft 21, at points on the outside of the bearings 22, are radius arms 23. These arms extend in opposite directions and move in unison with the shaft. The outer ends of these arms are formed with upper and lower spring seats, upon which helical expansion springs 24 and rest. The expansionspring- 24C' is interi'iosed'hetween the radiusarm and a lug- 26 formed upon a shackle arm 27. The spring 2a rests upon .the arm 23 and is covered at its upper end with a washer 28. A bolt 29 extends downwardly through the washer, an opening in the radius rod, and the lug 26.

The shackle arms 27 are mounted to freely rotate. upon the opposite ends of the shaft 21 and are heldin place by stop collars 30. These shackle arms extent in opposite n directions and yare positioned to agree `with the adjacent radius arms.

ing along` a level plane. The upward movement of the truck will act through the lower springI 25 of the complementary radius arm 23 to swing this arm upwardly and thus rotate the shaft 2l. rlhis movement will swing the opposite arm downwardly and, after compressing the spring 25, will act through the shackle to draw the truck frame downwardly. The amount of movement of the upwardly swinging` roller trame will be divided and the truck frame will move downwardly one half ofv the maximum movement of the roller frame, thus reducing the vibration of the main frame.

It will ffurtherbe observed that irrespective of road conditions the frame will be ycontinuously suspended upon springs which will act to absorb all minor vibrations of the two .track truck units. l

'Having thusdescribed my invention, what Iclaimfand desirel to secure by Letters Patent is:

l. In a tractor. construction, a main frame, roller Iframesv disposed at .the opposite sides of the main frame, and forming` a. part oit the self-laying vtrack units, a .transverse shaft carried by hangers upon the main frame, and upon whichthe roller frames are separately pivoted for vertical movement, a forward `transverse shaft carried by the main frame, oppositely extending` pressure arms fixed to said forward sha-lit, and yieldable connections between the roller frames and the pressure arms, whereby vertical movement of one roller framein one direction would tend to produce vertical movement ot the `opposite roller traine in the opposite direction. y l

2j In a :trame Suspension for tractors having a main frame and opposite independently movable roller Jframes, .transverse equalizer shaft rotatably carried by the .main iframe, pressure arms fixed to the opshackle arms ,and the pressure arms,'where Vby movement of one shackle Aarm in one direction willtend to produce yieldablemovement of the other shackle arm in the opposite direction.

3. A frame suspension for tractors having a main vframe and opposite roller frames comprising a transverse shaft rotatably carried by the main' :tram'mfreely pivoted shackle links `mounted fuponvthe opposite ends of the shaft, and lexibly connected tothe separate roller frames, pressure arms lixed upon the opposite ends of the shaft and extending oppositely to each other and parallel to complementary shackle linksya'lug extending from each ofthe shackleflinks, .and resides of the main 'frame and .pivotally connected thereto for roc-king movement in -a vertical plane, and an equalizing connection .between the main frame and each truck `traine comprising a transverseshafticarried by the, main frame, oppositely extendingv pressure arms iiredto said Yshaftl and connections-between, eachitruck frame and ad- ]acent pressure arm whereby vertical move- Vment of one truck frame in one .direction willatend to produce movement ot the opposite truck 'trame in the opposite direction.

:In -a tracto-r construciion,` a main frame,

va roller truck frame at each side thereof pivotally connected thereto ior 'rocking movement in a vertical plane, a shaft rotatablymounted upon them ain ft'rame, crank arms carried by the opposite ends of the sha'lt andfpivotally.connected with the roller truck trames, said arms being oppositely extended whereby rocking` movement ofone of the truck frames will :tend to produce .rockinar niOrementy of the opposite truck trame in the opposite direction. v

In testimony whereoi'I l have hereunto set my hand in the presenceot-two subscribing witnesses.

ELMER E. VVICKERSHAM. lll/witnesses: v

JOHN H. HERRING, W. W. HEALEY. 

